Domestic multi-channel programmable cochlear implants are now available. We are currently using it primarily for post-speech deaf patients, and for very profoundly deaf patients, if they can be selected as a candidate for cochlear implantation, the cochlear implant can be provided free of charge during this time. Our selection of patients with postlingual deafness: refers to deafness that occurs after an existing language and spoken language learning experience. Specific criteria: 1. 18 years of age or older, severe or very severe sensorineural deafness in both ears > 80 dBHL. 2. Ineffective or very poor hearing aids (latest FDA supplemental criteria, open phrase recognition test score ≤ 30% in the listening environment with optimal hearing aids for adults). 3.No contraindication to surgery. 4. Have the support of family and friends. 5. Have a correct understanding of cochlear implants and appropriate expectations. 6.Have appropriate psychological quality and subjective motivation.